The present invention relates to compositions, devices and method for controlling insects. Many recently-developed techniques used for the control of insects involve slow-release pesticide technology. The use of pest strips, collars, bands, and tags which have an insecticide contained throughout the substrate of the final device are described in U.S. Pat. Nos. 3,318,679; 3,944,662; 3,765,200; 3,942,480 and more recently, U.S. Pat. No. 4,195,075 which describes an insect-control device containing an insecticidally-active isomer of .alpha.-cyano-3-phenoxy-benzyl-.alpha.-isopropyl-4-chlorophenylacetate. One common feature of these devices is that they contain a pesticide throughout the substrate of said device.
Additionally, it appears the types of pesticides which are suitable for use in these devices is limited. A problem long-associated with these various devices is the method of preparation that frequently restricts the pesticide to be incorporated. Thus, only pesticides which are stable to the manufacturing process such as extrusion, injection molding, and the like are used. Also, incorporation of pesticides in such devices is limited due to interference of active ingredient with the formation of the final device, as for example, interference with the polymerization process. For example, since the final device contains the pesticide within the matrix material, a homogenous concentration of the pesticide must be present throughout the entire device in order for long term yet efficacious release of pesticide to occur. But often pesticide residues result with such devices that must be disposed. While several devices of this type are currently available, none contains combinations of pesticidally-active ingredients. Compositions of advantage for such pesticidal uses are disclosed in U.S. Pat. No. 4,340,608. In that patent, a phenoxybenzyl ester of a spirocarboxylic acid, a synthetic pyrethroid, with other insecticides for the control of insect pests is described. Compositions containing synthetic pyrethroids with other insecticides will become more desirable in the future, as insects begin developing resistance to these pyrethroids, a phenomenon which is already being reported. Devices containing such combination compositions will be beneficial for the control of insects.